1. Field of the Invention
The present invention relates to a foot pedal for a drum in which the drum head of a bass drum is struck by the depression of a foot board with the foot and more particularly to a foot pedal for a drum in which the feeling during the depression of the foot board can be varied to suit the player.
2. Prior Art
Various drum foot pedals of this type, in which a beater is caused to pivot by the depression of a foot board so that the beater strikes the drum head of a bass drum, have been proposed in the past (examples: Japanese Utility Model Application Publication No. 58-43035, etc.).
FIG. 4 shows a conventional example of a foot pedal for a drum. This conventional foot pedal may be described briefly as follows: A drum foot pedal 1 includes a pedal frame 2 which is positioned on the floor surface. This pedal frame 2 is made up of a frame main body 2A, a pair of left and right supporting columns 2B which are installed upright on the upper surface of the frame main body 2A, and a heel 2B which is connected to the frame main body 2A via a connecting member 3, etc. A clamping member (not shown in the drawing) which holds the tightening frame (or hoop) of a bass drum which is not shown in the drawings is attached to the frame main body 2A. A pivoting shaft 4 is installed between the upper ends of the pair of supporting columns 2B, 2B, and a rocker 5 is attached to the center of the pivoting shaft 4. Furthermore, a beater 6 which strikes the drum head is installed on the rocker 5 via a beater rod 7, and one end of a pedal depressing force transmission member 9 which transmits the depressing force of a foot board 8 to the beater 6 is connected to the rocker 5. The rocker 5 is formed so that it has a fan shape when seen from the side as shown in FIG. 4 or a "J" shape when seen from the side as shown in FIG. 5, etc, and one end of the pedal depressing force transmission member 9 is fastened to the upper circumferential surface of the rocker 5 by means of fastening screws 10. etc. A timing belt, a flexible leather or plastic band (FIG. 4) or a chain (FIG. 5), etc. may be used as the pedal depressing force transmission member 9. The foot board 8 is formed as a flat plate of sufficient size to accommodate the foot. The front end of the foot board 8 is connected to the other end of the pedal depressing force transmission member 9, and the rear end of the foot board 8 is connected to the heel 2C so that the foot board 8 is free to pivot. The upper end of a return spring 12 which imparts a pivoting habit to the foot board 8 in the return direction is connected to one end of the pivoting shaft 4 via a cam plate 13, and the lower end of this return spring 12 is connected to a spring receiving member 14 which is installed on the lower end of one of the supporting columns 2B.
In the drum foot pedal 1 constructed as described above, the foot board 8 is ordinarily maintained at a prescribed inclination with the front end thereof lifted as shown in the figures by the spring force of the return spring 12. When a depressing force is applied to the foot board 8 in this state, the pedal depressing force transmission member 9 is pulled downward, and as a result, the beater 6 pivots together with the pivoting shaft 4 and strikes the drum head of the bass drum. The maximum angle of depression of the foot board 8 in this case is approximately 15.degree.. When the depressing force is removed from the foot board 8 after the beater 6 has truck the drum head, the foot board 8 is caused to pivot upward by the spring force of the return spring 12, and the foot board 8 returns to its initial position.
However, in drum foot pedals of this type, the feeling (operating sensation) during depression of the foot board varies depending upon the shape of the rocker 5. For example, in the case of the rocker shown in FIG. 4 which is a fan-shaped rocker wherein the portion contacted by the pedal depressing force transmission member 9 is formed as a curved surface with a radius of R from the center of rotation (i.e., the center of the pivoting shaft 4), the rotational speed of the rocker remains constant regardless of the angle of rotation, even if a uniform depressing force is applied; as a result, the feeling is also constant. On the other hand, in the case of a rocker, as shown in FIG. 5, with a different shape in which the distance from the center of rotation to the fastened end 9a of the pedal depressing force transmission member 9 is short and the distance of the pedal depressing force transmission member 9 from the center of rotation increases moving away from the fastened end 9a in the direction of length of the pedal depressing force transmission member 9, the rocker 5 can be caused to rotate quickly by a small depressing force in the initial stage of depression, but it requires a gradually larger depressing force. Furthermore, when the depressing force is released immediately after the depressing operation, the rocker 5 returns quickly.
As seen from the above, the feeling during the depressing operation varies depending upon the shape of the rocker 5. However, since the shape of the rocker 5 itself is invariable, the feeling during the depressing operation cannot be changed to suit the player. In other words, the drum can only be played with a specified feeling which is determined by the shape of the rocker. Accordingly, in cases where it is desired to alter the feeling in accordance with the genre of the music, it is necessary to replace the drum foot pedal with a foot pedal equipped with a rocker whose shape is suited to the desired feeling.